After drilling each section of a subterranean wellbore that traverses one or more hydrocarbon bearing subterranean formations, individual lengths of metal tubulars are typically secured together to form a casing string that is positioned within the wellbore. This casing string provides wellbore stability to counteract the geomechanics of the formation such as compaction forces, seismic forces and tectonic forces, thereby preventing the collapse of the wellbore wall. Conventionally, the casing string is cemented within the wellbore. To produce fluids into the casing string, hydraulic openings or perforations must be made through the casing string and a distance into the formation. Following the perforation process, a production tubing string may be installed within the casing string such that fluid from the producing intervals may be transported to the surface therein.
Various downhole tools, such as tools for fluid flow control, sand control and pressure containment, may also be positioned in the wellbore. For example, such downhole tools may be coupled within the tubing string or may be lowered into the tubing string on a service string or other conveyance. For such downhole tools to perform their intended functions, they must be positioned in the wellbore at the proper depth. As such, knowledge of the precise location of one tubular string within or relative to another tubular string may be necessary when positioning tools downhole. Determination of a true downhole depth measurement, however, may be difficult due to, for example, inaccuracies in a depth reference log, elongation from thermal effects, buckling, stretching or friction effects, or other unpredictable deformations in the length of tubular strings positioned in the wellbore.
After certain downhole tools have been positioned within the wellbore, they may require actuation from a first operating state to a second operating state or require actuation between various operating states. For example, a packer may require actuation from an unset configuration to set configuration, while a fluid flow control device may require actuation between a closed configuration, a fully open configuration and various choking configurations. The actuation process for downhole tools may involve tubing movement, tool movement, application of wellbore pressure, application of fluid flow, dropping of balls on sleeves, hydraulic pressure, electronic means or combinations of the above. Following the actuation process, confirmation of the actuation of the downhole tool may be desirable.